The present invention relates to novel pasta products, in particular, long-life fresh pasta products and methods of producing the same comprising extrusion of dough (pasta dough) and acid(s)-treatment of pasta threads.
xe2x80x9cLong-Life Fresh Noodlesxe2x80x9d have shelflife as long as several months at room temperature regardless of their high water content, and they have popularly been marketed in recent years. They are called in Japan as xe2x80x9cLong-Life Noodles (LL Noodles)xe2x80x9d or xe2x80x9cFresh-Type Instant Noodlesxe2x80x9d. These long-life fresh noodles are usually produced by gelatinizing noodle threads, acidifying the gelatinized threads (boilied and/or steamed threads), hermetically packing the acidified threads, and pasteurizing them at about 100xc2x0 C. or below (But, in some cases, such pasteurization were performed at about 100xc2x0 C. or above). Long-life fresh noodles so produced can be served in a short time in comparison with (common) dried noodles, and can be served simply by pouring hot water thereinto though it depends on the type of noodles. Qualities of the long-life fresh noodles would be better than that of the noodle products produced by xe2x80x9cretortxe2x80x9d process and damaged drastically thereby.
But manufacturing process of the long-life fresh noodles needs a step to acidify noodle threads with acid(s) to obtain the longer shelflife, therefore, sourness (tartness) was often felt in the noodles. Some methods have been offered to eliminate such unacceptable taste, for example, by adding particular masking agents to the acid(s) or by adding alkaline agents into the soup.
Fairly strong sourness was often felt in the long-life fresh pasta products (e.g., macaroni, spaghetti) when they were produced along with the aforenoted producing method for the long-life fresh noodles using durum semolina (semolina of durum wheat) which is raw flour for conventional dried pasta products. Unfortunately, it was quite difficult to eliminate such undesirable sourness effectively.
The present inventors worked to solve such problems in the long-life fresh pasta products. They aimed at flours employed in the pasta products and speculated that the composition of wheat flour, and in particular, that of durum flour, may be the cause of such unacceptable taste. Then, they examined the correlation between the main components of durum flour and sourness. As a result, little correlation between protein content and sourness was confirmed. On the other hand, however, a close correlation between ash content and sourness was found.
In general, since the strength of sourness will be influenced by not only pH value but also acid concentration, even if the pH is the same, lowering acid concentration will be effective to weaken sourness. The present inventors found that ash in the flour suppressively acts to lower the pH of pasta. Further, they found that pasta threads can be effectively acidified with relatively small amount of acid, when flour of the lower ash content is employed. Thereby, problems on sourness in the conventional long-life fresh pasta products can be solved.
The present invention is directed to long-life fresh pasta products produced from flours having ash content of 0.45 wt % or less, preferably, 0.40 wt % or less. Then, the present invention is also directed to producing method of long-life fresh pasta products comprising the steps of: (1) preparing dough by mixing with water the raw flour having ash content of 0.45 wt % or less, preferably, 0.40 wt % or less (other materials such as starches, salts, alkaline agents, gelling agents, fats, oils, additives or the like may be added to the raw flour), (2) preparing pasta threads by extruding the dough, (3) gelatinizing the pasta by steaming and/or boiling the threads, (4) acidifying the gelatinized pasta with acids during or after the gelatinization, and (5) hermetically packing the acidified pasta into food-container and pasteurizing them.
Preferably, from about 1 to about 20 g of one or more of alginate-material(s) is(are) added to 1 kg of the raw flour. Such alginate-material(s) may include(s) alginic acids, salts of alginic acids and esters of alginic acids. Dough pH is adjusted from about 7 to about 9.
Further, preferably, from about 1 to about 20 g of one or more fat(s) and/or oil(s) is(are) added to the raw flour. They may include butter, butter oil, margarine and shortening.
The detailed description on the present invention are set forth as follows.
The term xe2x80x9clong-life fresh pasta productsxe2x80x9d used herein directs to any pasta produced through the producing methods of the long-life fresh noodles wherein the methods comprise extrusion of the pasta dough from an extruder and acid(s)-treatment of the pasta threads. The present long-life fresh pasta products may include any extruded products such as macaroni, spaghetti, shell or lasagna.
Ash content in the raw flour of the present invention (based on weight of wheat flour) is 0.45 wt % or less, preferably 0.40 wt % or less, and most preferably 0.38 wt % or less. Although wheat flour contains at least about 0.30 wt % of ash, any wheat flour having lower ash content can also be applied to the present invention. Wheat flours commercially distributed in Japan are classified into first-grade wheat flour, semi-first-grade wheat flour or the like according to their protein content. In general, since the first-grade wheat flour is made mainly from core portion of the wheat seed and has less ash content, it is most suitable to the present invention. Besides the first-grade wheat flour, semi-first-grade wheat flour (usual ash content of which is from about 0.40 to about 0.45 wt %) is also applicable to the present invention.
A mixture of two or more kinds of wheat flours of different ash content may also be employed. However, when such mixture is employed, it is also necessary to adjust its ash content to 0.45 wt % or less, preferably 0.40 wt % or less.
On the other hand, it is not preferable to employ semolina because the semolina (roughly ground durum wheat) commonly used for pasta products contains about as much as 0.7 wt % of ash. But, if the ash content is reduced to 0.45 wt % or less by selecting milling methods or the like, such processed semolina can also be employed in the present invention. When the normal durum semolina is used as a component of the raw flour, the amount of durum semolina to raw flour should be adjusted as low as 20 wt % or less, preferably 10 wt % or less.
Wheat flours are often classified based on the protein content as noted previously. But any wheat flour having ash content of 0.45 wt % or less can be employed in the present invention. Then, according to the present invention, wheat flours having protein content of from about 11 wt % to about 12 wt % are recommended to get the natural taste and texture of the dried pasta products.
As stated previously, a step to acidify the pasta threads is essential step for producing the long-life fresh pasta products of the present invention. But, such step often result in losing the firm texture felt by cooking dried pasta products even if the pasta is made from high-protein wheat flours. Further, gelling agents, proteins, enzymes or the like can be employed in the present invention to keep the firm texture. Gelling agents may include alginate-materials, xanthan gum, pectin, curdlan or the like. Proteins may include egg white, gluten or the like. Enzymes may include trans-glutaminase or the like. Among these materials or additives, alginate-materials are preferably added to get the desired pasta texture. The amount of the alginate-materials is from about 1 g to about 20 g per 1 kg of wheat flour, preferably, from about 3 g to about 6 g per 1 kg of wheat flour. Alginate-materials may include alginic acids, salts of alginic acids (e.g., sodium alginates, potassium alginates), esters of alginic acids (e.g., alginic acid propyleneglycol ester).
It is preferable to further incorporate alkaline agents into the raw flour when the alginate-materials are added to keep firm texture of the pasta products. Such alkaline agents may include sodium carbonate, potassium carbonate, kansui or the like. Amount of the alkaline agents is the amount needed to adjust dough pH into neutral to alkaline zone, preferably from about pH 7 to 9 when water is added thereto.
In accordance with the other embodiment of the present invention, fat(s) and/or oil(s) is(are) preferably incorporated into the raw flour to improve flavor and texture of the present long-life fresh pasta products. They may include butter, butter oil, margarine and shortening. By employing it(them), taste and mouth-feel of the common dried pasta are realized, and sourness and sour-odor remained in the acidified pasta are effectively removed (See, Example 4). The amount of it(them) is from about 1 g to about 20 g per 1 kg of raw flours, preferably, from about 2 g to about log per 1 kg of raw flours. Other raw materials or additives can optionally be added to the raw flours. They may include starches, proteins, salts, colours, gelling agents, fats and the like. With respect to the starches, modified starches are recommended to avoid unacceptable deterioration of flavor and texture. Such modified starches may include starch-esters, starch-ethers and crosslinked starches.
Dough is prepared by mixing raw flours and, if necessary, raw materials or additives mentioned above, and kneading the mixture with water. The dough so prepared are then extruded. The raw materials or additives such as alginate-materials can be added in a powder form to raw flour. They can also be dissolved into water and be added to the flour. Warm water can also be employed. Pasta of the present invention is made by adding water to a mixture of raw flour and raw materials, preparing dough by kneading them with a mixer, extruding the dough so prepared with an extruder. As an extruder, screw extruder is preferable to realize the desirable firm pasta. When the dough is extruded with an extruder, it is deaerated under reduced pressure in order to realize desirable dense-tissued pasta. The pasta dough are preferably kneaded and/or extruded under the reduced pressure of 200 mmHg (absolute pressure) or less. Extruding pressure is 40 kg/cm2 or more, preferably 80xcx9c130 kg/cm2.
Openings on an extrusion head are shaped according to the form of pasta to be produced. For example, when long-pasta like spaghetti is going to produce, cross-sectional form of discharge-openings on the extrusion head is shaped into circular or the like. Pasta can also be prepared by applying dough to an extruder, extruding them from an elongated openings on the extrusion head and processing the extruded sheet into the pasta threads. When short-pasta like macaroni, shell or farfallina are going to made, any of the following methods is used, namely, (i) to cut the extruded dough from the openings on the extrusion head, (ii) to form the short-pasta by extruding the dough into shaped molds, or (iii) to form the short-pasta by punching the dough sheet prepared through extrusion of dough from elongated openings on the extrusion head.
The term xe2x80x9cpasta threadsxe2x80x9d used herein directed to any thread and short pasta prepared through such extrusion procedure.
Although pasta threads so extruded can be once dried like common dried pasta products, the present invention does not always need such drying step. Extruded threads and/or dried threads are gelatinized by steaming or boiling them (i.e., the threads are partially or completely cooked at this step). Such steaming and boiling can be performed sequentially or concurrently.
The gelatinized pasta threads are then acidified to adjust pH of pasta threads to pH below 4.6, preferably from about 4.0 to about 4.5. Acidification of the pasta threads may be performed by dipping the pasta threads into an acid solution or by spraying an acid solution to the pasta threads. Acid solution may includes an aqueous solution of organic acids including lactic acid, citric acid, acetic acid or the mixture thereof. When the pasta threads are gelatinized by boiling, gelatinization and acidification of the pasta threads can be performed concurrently by putting the pasta threads into the boiled acid(s) solution.
Acidified pasta threads are hermetically packed into food-container and are pasteurized. The term xe2x80x9cfood-containerxe2x80x9d used herein may includes both hard and soft container(s), for example, vessels made of ceramic or metal, bags or pouches made of plastic resin. Acidified pasta threads are then preferably pasteurized at a temperature of from about 90xc2x0 C. to about 100xc2x0 C. Pasteurization of the pasta threads is usually conducted under 100xc2x0 C. or below in the art, but the present pasta threads can also be pasteurized under 100xc2x0 C. or above. For example, the pasta threads are pasteurized at 95xc2x0 C. for 20 minutes or more in a steam chamber. The pasteurized pasta threads are then cooled, and are called at this point as xe2x80x9clong-life fresh pasta productsxe2x80x9d of the present invention. The present long-life fresh pasta products are further packed into cup-form hard vessels or plastic bags, and are distributed under the room temperature.
The long-life fresh pasta products according to the present invention can be served, for example, by cooking the pasta threads taken out from the pouch by (i) simply pouring hot-water onto the pasta, (ii) pouring hot-water onto the pasta and discarding the hot-water, (iii) simply boiling the pasta, or (iv) boiling the pasta with hot-water and discarding the hot-water. When the pasta is going to be cooked through the procedure (iii) or (iv), lower water content in the pasta threads is recommended to get the desirable pasta texture.